Seal for rotary regenerative heat exchanger

ABSTRACT

A seal for engagement with an end face of the matrix of a rotary regenerative heat exchanger is formed from a plurality of blocks arranged end-to-end in a guide housing, adjacent end faces of the blocks being shaped to form a joint permitting articulation of adjacent blocks about a pivotal axis extending transversely of the blocks and parallel with the plane of the end face of the matrix, the blocks being of sufficiently short length and sufficient in number to permit the seal to conform to the surface profile of the end face of the matrix.

United States Patent [191 Penny [451 May 13,1975

[ 1 SEAL FOR ROTARY REGENERATIVE HEAT EXCHANGER [76] Inventor: Robert Noel Penny, 12 Alderbrook,

Solihull, England 22 Filed: Mar. 27, 1973 211 App]. No.: 345,272

[30] Foreign Application Priority Data Mar. 28, 1972 United Kingdom 14406/72 [52] US. Cl. 165/9; 165/8; 277/199; 277/26 [51] Int. Cl. F28d 19/00 [58] Field of Search 165/9, 81; 277/199, 192,

[56] References Cited V UNITED STATES PATENTS 2,747,843 5/1956 Cox et al. 165/9 3,273,904 9/1966 Chapman et a1 165/9 X Gignac 277/199 X FOREIGN PATENTS OR APPLICATIONS 1,136,122 12/1968 United Kingdom 165/10 842,948 7/1952 Germany 165/9 1,054,474 4/1959 Germany 165]) Primary Examiner-A1bert W. Davis, Jr. Attorney, Agent, or Firml'lauke, Gifford, Patalidis 8L Dumont 57 ABSTRACT A seal for engagement with an end face of the matrix of a rotary regenerative heat exchanger is formed from a plurality of blocks arranged end-to-end in a guide housing, adjacent end faces of the blocks being shaped to form a joint permitting articulation of adjacent blocks about a pivotal axis extending transversely of the blocks and parallel with the plane of the end face of the matrix, the blocks being of sufficiently short length and sufficient in number to permit the seal to conform to the surface profile of the end face of the matrix.

6 Claims, 11 Drawing Figures PATENTEU HAY I 3l975 SHEET 2 BF 2 FIG.11

SEAL FOR ROTARY REGENERATIVE HEAT EXCHANGER BACKGROUND OF THE INVENTION I. Field of the Invention The invention relates to a seal for a rotary regenerative heat exchanger.

II. Description of the Prior Art Seals of this kind are disclosed in the Specification of my co-pending Pat. application No. 317,823 in which seals in the shape of a closed figure are urged into rubbing engagement or close proximity to the end faces of a disc-like rotatable matrix of a rotary regenerative heat exchanger of a gas turbine engine. In the foregoing Specification there is disclosed a seal formed from blocks arranged end-to-end to form the continuous periphery of the closed figure seal.

Under operating conditions the matrix will be heated to a high temperature which may result in the matrix being distorted to a dished shape or where 'it is of large diameter it may not be perfectly flat. Under such conditions the seals,even when formed from blocks arranged end-to-end as taught in. the foregoing Application cannot follow the dished shape of the matrix and leakage of air or gas will occur between the end faces of the matrix and the seals.

SUMMARY OF THE PRESENT INVENTION According to the invention, a seal for engagement with an end face of the matrix of a rotary regenerative heat exchanger or a portion of a seal is formed from a plurality of blocks arranged end-to-end in a guide housing, adjacent end faces of the blocks being shaped to form a joint permitting articulation of adjacent blocks about a pivotal axis extending transversely of the blocks and parallel with the plane of the end face of the matrix, the blocks being of sufficiently short length and sufficient in number to permit the whole seal or said portion thereof to conform to the surface profile of the end face of the matrix.

One of the end faces of a pair of adjacent blocks may be of cylindrical concave shape and the adjacent end face of the co-operating block may be of complementary cylindrical convex shape.

Alternatively both adjacent end faces of a pair of adjacent blocks may be of concave cylindrical shape, a cylindrical roller being positioned between the bloc-ks and located in the concave end faces.

Where an intervening roller is not provided between adjacent blocks, the adjacent blocks may abut together the rollers may be of a synthetic plastics material, such in the manner of a knuckle joint or they may be hinged by a pin.

The blocks may be resiliently biased into engagement with the adjacent end face of the matrix by spring means or by a pressurized fluid. Where the portion of the seal constructed in accordance with this invention is a straight bar seal, the blocks may be urged in their guide housing by spring means or a pressurized fluid into sealing engagement with an arcuate seal with which the bar seal is to form a closed figure.

The blocks from which the seal is constructed may be made from any suitable material for rubbing seals and capable of withstanding the working temperature of the seal. For example, at the hotter end of the matrix, the seal blocks may be made of carbon or nickel oxide or be coated with nickel oxide or other material capable as for example, nylon; but at the hotter end, the rollers would be made of carbon or nickel oxide or another material capable of withstanding a high operating temperature.

The seal blocks of a seal, or a portion thereof, constructed in accordance with this invention, may be made of different materials having differing coefficients of linear expansion, the materials and the lengths of respective blocks being so chosen that the effective coefficient of linear expansion of the seal or seal por-. tion is substantially the same as that of supporting structure therefor, the heat exchanger housing or another portion of the seal. For example, where an arcuate seal portion is engaged by a bar seal portion constructed in accordance with this invention and the bar seal portion extends diametrically or chordwise in an annular housing, also containing the arcuate seal portion, the blocks from which the bar seal portion is con structed may be made of different materials having different coefficients of linear expansion and the lengths of the blocks of different materials may be so chosen that the effective coefficient of linear expansion of the bar seal portion is substantially the same as that of the arcuate seal portion and the annular seal housing, whereby on expansion or contraction of the whole seal and the housing, the bar seal portion will remain in constant engagement with the arcuate seal portion and there will be substantially no relative expansion or contraction between the bar seal portion and the annular housing.

The blocks from which the seal or seal portion is constructed in accordance with this invention may be provided with co-operating longitudinal grooves in their seal faces to control the effective sealing area of the whole seal as taught in my aforesaid co-pending Patent Application.

BRIEF DESCRIPTION OF THE DRAWING By way of example, several constructions of articulated seals in accordance with the invention are now described with reference to the accompanying drawings, in which:-

FIG. 1 is a plan view of a heat exchanger disc showing a closed figure seal to which the invention is applied;

FIG. 2 is a cross-sectional view to a larger scale of a portion of a first construction of the seal shown in FIG.

FIG. 3 is a section on the line IIIIII in FIG. 2;

FIG. 4 is a view similar to FIG. 3 of a portion of a second construction of seal;

FIG. 5 is a view similar to FIG. 4 but to a larger scale of aknuckle joint of the sealshown in FIG. 4;

FIG. 6 is a section on the line VIVI in FIG. 5;

FIG. 7 is a view similar to FIG. 4 of a portion of a third construction of seal;

FIG. 8 is a view in the direction of arrow VIII of the seal portion shown in FIG. 7;

FIG. 9 is a view similar to FIG. 3 of a portion of a forth construction of seal;

FIG. 10 is a modification of the seal portion shown in FIG. 3, and

FIG. 11 is a view in the direction of arrow XI of the seal portion shown in FIG. 10.

DETAILED DESCRIPTION OF THE PRESENT INVENTION The constructions of seal shown in FIGS. 2 to 11 may be employed in any longitudinal portion of the closed figure seal 1, 2 shown in FIG. 1, although the invention is particularly applicable to the diametral or chordwise portion 1 of the seal. The need for permitting at least the diametral or chordwise portion 1 of the seal to articulate is because where a heat exchanger matrix is in the form of a rotatable disc 3 its end faces against which the seals engage may be distorted due to temperature change on operation of the heat exchanger and instead of being flat they become dished or undulate in some other way. Furthermore where a matrix disc is of large diameter its end faces may not be perfectly flat. By making the seal, and particularly the diametral or chordwise portion 1, of articulated sections, the sections can articulate toward or away from the plane of the end face of the disc 3 and thereby remain in sealing contact with the end face of the disc 3 despite the end face being of dished or other non-flat form.

Referring to FIGS. 2 and 3, the first construction of seal comprises a plurality of short sealing blocks 4, 5 which are arranged end-to-end to form the complete seal or seal portion 1. Adjacent faces of adjacent blocks are of mating concave and convex part-cylindrical shape so that the blocks can freely articulate with respect to each other and maintain an effectively continuous seal along the length of the complete seal or seal portion 1. The blocks are guided in a stationary channel-shaped housing 6 extending along the length of the seal or seal portion 1. The side edges 7 of the blocks closely engage a liner 8 in the channel of the housing 6 permitting the blocks to slide into or out of the channel in the direction of arrows X in FIG. 2 and to sealingly close a compartment 9 in the channel extending along the whole length thereof and to which compressed air is applied through a duct 10. During operation of the heat exchanger the blocks 4, 5 are maintained in contact with the adjacent end face of the rotating matrix disc 3 by compressed air or other pressurized fluid applied to the compartment 9 and the concave and convex faces of the blocks 4 and 5 permit the blocks to articulate relatively to each other to permit the blocks to follow the dished or other non-flat profile of the end face of the disc 3.

Instead of the blocks 4 and 5 having mating convex and concave adjacent faces, the adjacent faces of blocks 11 may be formed with semi-cylindrical grooves between which cylindrical rollers 12 are positioned to form the articulated joints as shown in FIG. 4. To prevent leakage of fluids (e.g. air and gas) between which heat is being exchanged along the length of the roller and between adjacent blocks 11, i.e. from one side of the seal to the other, a seal 13 is inserted in transverse grooves 14 and 15 formed in the roller and the blocks 11 respectively, as shown in FIGs. 5 and 6.

FIGS. 7 and 8 show the third construction of seal in which adjacent seal blocks 16 are provided with interfitting tongues 17 and grooves 18 having adjacent end faces spaced apart at 19 and 20 to permit sufficient free articulation. Adjacent blocks 16 are hinged together by hinge pins 21 extending through aligned holes in the blocks through the tongues and walls of the sockets.

In all the foregoing constructions the blocks are urged into contact with the disc face by compressed air or other pressurized fluid applied to the compartment 9 in the channel of the housing 6 shown in FIG. 2. Alternatively the blocks may be urged into engagement with the adjacent end face of the matrix disc 3 as shown in FIG. 9 by spring strips or wires 22 located in recesses 23 in the rear faces of blocks 24, 25, i.e. the faces opposite the faces engaging the matrix disc 3 and engaging a wall of the housing 6 which as shown in FIGS. 2 and 3 is formed with a channel guiding the blocks toward and away from the plane of the end face of the matrix disc 3.

Where the diametral or chordwise portion 1 of the seal is constructed separately from another portion such as the portion 2 in FIG. 1 of C-shape, it is necessary to ensure that the seal portion 1 is maintained in sealing engagement at its ends with the seal portion 2. To enable this to be performed at least one of the blocks, for example a block 4, of FIG. 3 is constructed from two co-operating parts 26, 27 each having partwidth portions which are arranged side-by-side in the housing 6 to form a composite block as shown in plan in FIG. 11. Adjacent edges of the two parts 26, 27 in the faces thereof in the compartment 9 of the housing 6 are chamfered to form two non-aligned V-shaped grooves 28, 29 spaced apart between the convex or concave end faces of the composite block. Thus when compressed air or other pressurized fluid is applied to the compartment 9 to urge the blocks into sealing engagement with the matrix disc 3, there will also be sideways forces tending to push the parts 26, 27 of the blocks apart thereby increasing the length of the whole articulated sealportion and urging the end blocks into engagement with the seal portion 2.

Alternatively springs such as springs 22 shown in FIG. 9 could be arranged to urge the block parts 26, 27 apart as well as urging the blocks into engagement with the matrix disc.

As aforesaid the blocks of the seals are made of a material capable of withstanding the working temperature. For example, at the hotter end of the matrix, the seal blocks may be made of carbon or of nickel oxide or be coated with nickel oxide. Similarly the rollers 12 or hinge pins 21 could be made of a material selected to withstand the working temperature to which the seal is to be subjected. Furthermore, some of the blocks of each of the seal constructions as hereinbefore described may be made of one material and at least some of the remaining blocks may be made of a different material, the materials having different coefficients of linear expansion, the materials and the lengths of the respective blocks being so chosen that the effective coefficient of linear expansion of the seals is substantially the same as that of the seal housing.

What I claim is:

1. A rotary regenerative heat exchanger havinga disk-like rotatable matrix and including a pair of seals of which one engages one end face of the matrix and the other engages the other end face of the matrix, at least a portion of one of the seals being formed from a plurality of blocks of which some are made of one material and at least some of the remaining blocks are made of another material having a different coefficient of linear expansion, said blocks arranged end-to-end in a guide housing, adjacent end faces of the blocks being shaped to form a joint permitting articulation of adjacent blocks about a pivotal axis extending transversely of the blocks and parallel with the plane of the end face of the matrix, the blocks being of sufficiently short length and sufficient in number to permit said portion of the seal to conform to the surface profile of the end face of the matrix, and the materials and the lengths of the respective blocks being such that the effective coefficient of linear expansion of the seal is substantially the same as that of the guide housing.

2. A rotary regenerative heat exchanger as claimed in claim 1 in which one of the end faces of a pair of adjacent blocks is of cylindrical convex shape and the adjacent end face of the co-operating block is of complementary cylindrical concave shape.

3. A rotary regenerative heat exchanger as claimed in claim 1 in which each pair of adjacent blocks have end faces formed respectively with a groove and an interfitting tongue, and a hinge pin extends through the tongue into the adjacent walls of the groove.

4. A rotary regenerative heat exchanger as claimed in claim 1 in which the blocks are arranged to be urged outwardly of the guide housing by fluid pressure acting directly on the blocks to urge them into sealing engagement with the end face of the heat exchanger matrix.

5. A rotary regenerative heat exchanger as claimed in claim 1 including spring means by which the blocks are urged outwardly of the guide housing, said spring means acting between the guide housing and the end faces of the blocks opposite the seal faces thereof.

6. A rotary regenerative heat exchanger as claimed in claim 1 in which at least one of the blocks is formed of two parts arranged to be pushed apart, thereby to increase the length of the seal, when the block is urged into sealing engagement with the matrix end face. 

1. A rotary regenerative heat exchanger having a disk-like rotatable matrix and including a pair of seals of which one engages one end face of the matrix and the other engages the other end face of the matrix, at least a portion of one of the seals being formed from a plurality of blocks of which some are made of one material and at least some of the remaining blocks are made of another material having a different coefficient of linear expansion, said blocks arranged end-to-end in a guide housing, adjacent end faces of the blocks being shaped to form a joint permitting articulation of adjacent blocks about a pivotal axis extending transversely of the blocks and parallel with the plane of the end face of the matrix, the blocks being of sufficiently short length and sufficient in number to permit said portion of the seal to conform to the surface profile of the end face of the matrix, and the materials and the lengths of the respective blocks being such that the effective coefficient of linear expansion of the seal is substantially the same as that of the guide housing.
 2. A rotary regenerative heat exchanger as claimed in claim 1 in which one of the end faces of a pair of adjacent blocks is of cylindrical convex shape and the adjacent end face of the co-operating block is of complementary cylindrical concave shape.
 3. A rotary regenerative heat exchanger as claimed in claim 1 in which each pair of adjacent blocks have end faces formed respectively with a groove and an interfitting tongue, and a hinge pin extends through the tongue into the adjacent walls of the groove.
 4. A rotary regenerative heat exchanger as claimed in claim 1 in which the blocks are arranged to be urged outwardly of the guide housing by fluid pressure acting directly on the blocks to urge them into sealing engagement with the end face of the heat exchanger matrix.
 5. A rotary regenerative heat exchanger as claimed in claim 1 including spring means by which the blocks are urged outwardly of the guide housing, said spring means acting between the guide housing and the end faces of the blocks opposite the seal faces thereof.
 6. A rotary Regenerative heat exchanger as claimed in claim 1 in which at least one of the blocks is formed of two parts arranged to be pushed apart, thereby to increase the length of the seal, when the block is urged into sealing engagement with the matrix end face. 